Acute Exercise before Dialysis Is as Cardioprotective as during Dialysis: A Randomized Controlled Trial

Abstract

Background Hemodialysis induces left ventricular regional wall motion abnormalities (RWMAs) due to myocardial hypoperfusion. Although acute intradialytic exercise (IDE) has shown cardioprotective effects, its routine implementation faces feasibility challenges, and the potential of predialysis exercise as an alternative remains unexplored. This study aimed to compare the effect of predialysis exercise and IDE on hemodialysis-induced myocardial stunning. Methods In this open-label, randomized cross-over trial, 25 patients with ESKD underwent to each of three hemodialysis conditions, administrated in random order: standard hemodialysis (HD-CONT), hemodialysis with IDE (HD-PER), and hemodialysis preceded by exercise (HD-PRE). Two-dimensional echocardiography and whole blood viscosity (WBV) measurements were performed both immediately before hemodialysis onset (T0) and at peak stress of hemodialysis (Tpeak). Left ventricular longitudinal strain from an 18-segment model was used to assess the presence of RWMAs. Regular monitoring of cardiovascular hemodynamics was set up with measurements staggered every 30 minutes. Results Compared with HD-CONT, there was a significant reduction in RWMAs during both HD-PER (estimated difference, 1.60 segments; 95% confidence interval, 0.09 to 3.10; P = 0.04) and HD-PRE (estimated difference, 1.72 segments; 95% confidence interval, 0.21 to 3.22; P = 0.02). The magnitude of the exercise-induced reduction in myocardial stunning did not differ between HD-PER and HD-PRE (P = 0.86). Apart from the exercise period itself, kinetics of all hemodynamic variables were similar between HD-CONT and HD-PER, whereas they were totally similar between HD-CONT and HD-PRE. No associations of changes in RWMAs and hemodynamics variables between HD-CONT versus HD-PRE or HD-PER were found (P > 0.42). Comparing HD-CONT versus HD-PER, WBV was preserved in HD-PER and changes in RWMAs were associated with changes in WBV at high shear rates (225 s-1: P = 0.006; 90 s-1: P = 0.04). Conclusions Physical exercise performed before hemodialysis provides cardioprotective effects comparable with those of IDE. The mechanisms behind these benefits do not seem to involve hemodynamic factors.